Near the end of the First World War, an assortment of groups contested to proclaim an independent Polish state. In early November 1918, a socialist provisional government under Ignacy Daszyński declared independence, while a separate committee in Kraków claimed to rule West Galicia. In Warsaw, the German-Austrian appointed Regency Council agreed to transfer political responsibilities to Marshal Józef Piłsudski, recently released from Magdeburg fortress, as Chief of State of the new Polish nation. Piłsudski summoned Daszyński to the capital to form a government, where Piłsudski agreed to appoint Daszyński as the republic's first prime minister. Daszyński's premiership, however, remained brief, after the politician failed to form a workable coalition. Piłsudski turned instead to Jędrzej Moraczewski, who successfully crafted a workable government for the Second Republic's first months of existence.
The Small Constitution of 1919 outlined Poland's form of government, with a democratically elected Sejm, a prime minister and cabinet, and an executive branch. Despite outlining a parliamentary system, the Small Constitution vested many executive powers onto Piłsudski's position as Chief of State. The executive branch could select and organize cabinets (with the Sejm's consent), be responsible to the ministries for their duties, and require the countersignature of ministers for all official acts. By the early 1920s, rightist nationalists within parliament, particularly Roman Dmowski and other members of the Popular National Union party and the Endecja movement, advocated reforms to the republic's structure to stem the authority of the chief of state (and ultimately Piłsudski) while increasing parliamentary powers. The result was the Sejm's passage of the March Constitution of 1921. Modeled after the Third French Republic, the March Constitution entrusted decision-making exclusively within the lower-house Sejm. The newly created presidency, on the other hand, became a symbolic office devoid of any major authority, stripped of veto and wartime powers.
Deriving authority from the powerful Sejm, the prime minister and the council of ministers, in theory, faced few constitutional barriers from the presidency to pass and proceed with legislation. In reality, however, the premiership remained extraordinarily insecure due to the harsh political climate of the early Second Republic, marked by constant fluctuating coalitions within parliament. Fourteen governments and eleven prime ministers rose and fell between 1918 and 1926, with nine governments alone serving between the five-year March Constitution era. Deeply frustrated with the republic's chaotic "sejmocracy" parliamentary structure, Piłsudski led rebellious Polish Army units to overthrow the government in the May Coup of 1926, effectively ending the Second Republic's brief experiment with parliamentary democracy, as well as the prime minister's free and popular elected mandate for the next sixty years.
Distrustful of parliamentary democracy, Marshal Piłsudski and his Sanation movement assumed a semi-authoritarian power behind the throne presence over the premiership and presidency. Piłsudski's August Novelization of the 1921 Constitution retained the prime minister's post and the parliamentary system, though modified the president's powers to rule by decree, dismiss the Sejm, and decide budgetary matters. By the mid-1930s, Piłsudski and fellow Sanationists further stripped parliament and the premier's powers by enacting a new constitution, effectively establishing a strong "hyper-presidency" by 1935. The new constitution allowed for the president to dismiss parliament, the right to freely appoint and dismiss the prime minister, members of the cabinet and the judiciary at will, and promulgated the presidency as the supreme power of the state. Until the outbreak of the Second World War and the resulting exiling of the Polish government, the Sanation movement remained at the helm of a government dominated by the presidency with a weak, subordinate prime minister.